A combined analysis of genomic and primary protein structure defines the phylogenetic relationship of new members if the T-box family

Genomics. 1998 Feb 15;48(1):24-33. doi: 10.1006/geno.1997.5150.

Abstract

T-box genes form an ancient family of putative transcriptional regulators characterized by a region of homology to the DNA-binding domain of the murine Brachyury (T) gene product. This T-box domain is conserved from Caenorhabditis elegans to human, and mutations in T-box genes have been associated with developmental defects in Drosophila, zebrafish, mice, and humans. Here we report the identification of three novel murine T-box genes and an investigation of their evolutionary relationship to previously known family members by studying the genomic structure of the T-box. All T-box genes from nematodes to humans possess a characteristic central intron that presumably was inherited from a common ancestral precursor. Two additional intron positions are also conserved with the exception of two nematode T-box genes. Subsequent intron insertions, potential deletions, and/or intron sliding formed a structural basis for the divergence into distinct subfamilies and a substrate for length variations of the T-box domain. In mice, the 11 T-box genes known to date can be grouped into seven subfamilies. Genes assigned to the same subfamily by genomic structure show related expression patterns. We propose a model for the phylogenetic relationships within the gene family that provides a rationale for classifying new T-box genes and facilitates interspecific comparisons.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cell Line
  • Conserved Sequence
  • DNA-Binding Proteins / genetics*
  • Exons
  • Introns
  • Mice
  • Molecular Sequence Data
  • Phylogeny*
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Transcription Factors / genetics*

Substances

  • DNA-Binding Proteins
  • Transcription Factors

Associated data

  • GENBANK/AF013281
  • GENBANK/AF013282
  • GENBANK/AF013283